Tundish dumping and skewing device for continuous casting



Aug. 18, 1970 w. R. SMITH 3,524,494

' TUNDISH DUMPINGI AND SKEWING DEVICE FOR CONTINUOUS CASTING Filed March28, 1968 2 SheetS -Sheet 1 v INVENTOR v M760! 1?- Smifh Aug. 18, 1970 w.R. SMITH 3,524,494

TUNDI SH DUMPING AND SKEWING DEVICE FOR CONTINUOUS CASTING Filed March28, 1968 2. Sheets-Sheet 2 dh/a i 55 6 1331 60 Q I| I l I *1 a l rINVENTOR g 8 mm A. sm/m United States Patent "ice 3,524,494 TUNDISHDUMPING AND SKEWING DEVICE FOR CONTINUOUS CASTING Wilbur R. Smith,Allentown, Pa., assignor to Bethlehem Steel Corporation, a corporationof Delaware Filed Mar. 28, 1968, Ser. No. 716,763 Int. Cl. B22d 11/10,41/04 US. Cl. 164-281 4 Claims ABSTRACT OF THE DISCLOSURE A tundish,adapted to be rotated about its trunnions, is disposed above a verticalmold. The trunnion seats are pivotally mounted and independently movablewhereby the tundish may be skewed about a vertical axis. A hydrauliccylinder controls the rotation of the tundish about its trunnionswhereby the tundish can be leveled prior to casting and dumped followingcasting. The cylinder is connected to the trunnion seat and the tundishwhereby skewing of the tundish results in substantially no rotation ofthe tundish about its trunnions.

BACKGROUND OF THE INVENTION This invention relates to continuous castingapparatus, and more particularly to apparatus for centering the streamsof molten metal pouring from a tundish into a vertical continuouscasting mold without affecting the level position of the tundish.

In the continuous casting of slabs of molten metal, e.g. steel, themolten metal is generally poured from a ladle into a tundish and thenceinto a vertical mold. The tundish is a hollow vessel, lined with arefractory material, and generally has a plurality, e.g. two or more, ofnozzles, also lined with a refractory material, in the bottom thereof.

It is vitally important that the streams of molten metal leaving thenozzles enter the mold as symmetrically as possible in order to ensureuniform solidification. Thus, the nozzles should be centered withrespect to the geometric center lines of the cross section of the mold.

Frequently, the nozzles of a tundish are disposed along a line which isnot centered with respect to the mold cross section. It is thereforeessential to skew the tundish, i.e. rotate it about a vertical axis, tocenter it above the mold. However, the skewing of the tundish must notresult in tilting of the tundish, as tilting of the tundish will causethe metal to leave the nozzles at an angle, and the metal falling intothe mold will build up along one side thereof with consequent nonuniformcooling.

In addition to the foregoing, the tundish should be provided with meansfor controlling the rotation of the tundish about its trunnions. Thatis, this means should be capable of initially leveling the tundish priorto the casting operation, and capable of dumping the metal out of thetundish after the casting operation is completed.

This means should further be capable of rotating the tundish through arelatively large angle, e.g. 109, whereby no metal is left therein afterdumping. This means must, however, be connected to the tundish in such amanner that skewing of the tundish does not appreciably affect the levelposition of the tundish.

It is an object of this invention to provide improved means for skewingand dumping a tundish, the skewing and dumping motions beingsubstantially independent of each other.

SUMMARY OF THE INVENTION I have discovered that the foregoing object canbe attained by providing a support frame, comprising two horizontalmembers disposed above a vertical continuous 3,524l,4194 Patented Aug.18, 1970 casting mold, pivotally mounted trunnion seats disposed on saidsupport frame, a tundish provided with trunnions rotatably mounted insaid trunnion seats, extensible and retractile means linking each ofsaid trunnion seats and said support frame, slidable means mounted oneach of said horizontal members, means pivotally connecting said tundishand said slida-ble means for controlling the rotation of said tundishabout its trunnions, and means connecting said trunnion seats and saidslidable means whereby any change in the horizontal position of saidtundish trunnions as a result of skewing results in substantially norotation of said tundish about its trunnions.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. la and 1b are diagrammatic planviews of a tundish having nozzles disposed above the mold of acontinuous slab casting machine.

FIG. 2 is a side elevation showing the tundish in a level position.

FIG. 3 is a side elevation showing the tundish in a dumping position.

FIG. 4 is a plan view, partly in section, showing details of the skewingand dumping mechanism.

FIG. 5 is an enlarged sectional view showing details of the skewing anddumping mechanisms.

FIG. 6 is a sectional view taken along the lines 6-6 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1a shows a tundish 10disposed above the mold 12 of a continuous slab casting machine. In thebottom of said tundish are three nozzles 14 through which molten metalleaves the tundish 10 and falls into the mold 12. As can be seen, thenozzles 14 are not centered above the longitudinal center line 16 of themold 12. It is therefore necessary to skew the tundish 10, in thedirection of the arrows, until it assumes the position shown in FIG. 1b.(The amount of misalignment ShOWn in FIG. 10 has been greatlyexaggerated for the sake of clarity. In general, the tundish need not beskewed more than about one-half nch on each side thereof.) The angle ofskew 18, which is herein defined as the angle between the center line 20of the tundish 10 before skewing and the center line 22 of the tundish10 after skewing, is usually less than one degree, e.g. i051'.

The tundish 10 is supported above the mold 12 by means of a framework 24comprising beams 26 and columns 28. The framework 24, which is providedwith suitable trusses (not shown), is adapted to be raised, lowered, andmoved horizontally by well known means (also not shown).

Each beam 26 is provided with a bracket 30 on which a trunnion seat 32is pivotally mounted by means of a pm 34. Each column 28 is providedwith a bracket 36 on which one end of a turnbuckle-like device 38 ispivotally mounted, the other end of the device 38 being pivotallymounted on the trunnion seat 32. The device 38 comprises a shaft 40having a wheel 42 mounted thereon. One end of the shaft 40 is free torotate within shaft housing 44, said housing being pivotally mounted onbracket 36 by means of pin 46. The other end of shaft 40 threadedlyengages shaft housing 48, housing 48 being pivotally mounted on trunnionseat 32 by means of pin 50.

Each trunnion seat 32 is provided with a slot bearing 52 in which onetrunnion 54 of the tundish 10* rests. A lock plate 56 is bolted acrossthe top of the slot bearing. Each trunnion 54 is provided with aspherical bearing surface to permit skewing of the tundish 10 withoutbinding the trunnions. Each trunnion is disposed in substantial verticalalignment with its respective trunnion seat pivot whereby small rotarymovements of said trunnion 3 seat result in substantially entirelyhorizontal motion of said trunnion,

A connecting rod 58 is provided which links the trunnion seat 32 to ablock 60 slidably mounted on the beam 26. As is shown in detail in FIGS.4, and 6, each connecting rod 58 comprises plates 62 which are pivotallyconnected to trunnion seat 32 by pin 64 and spacer blocks 65. The otherend of the connecting rod 58 is pivotally connected to block 60 by pin66 and spacer blocks 68.

Interposed between the spacer block 68 is a selfaligning bushingassembly 70 which is connected to one end 72 of a hydraulic cylinder 74.The bushing assembly 70 is mounted within the block 60 by the pin 66 andcom prises a spherical bearing 76. The block 60 is adapted to slidealong a bearing surface of plate 78 disposed on the beam 26.

The hydraulic cylinder 74 has a shaft 80 connected to the pistonthereof. The end of the shaft 80 is connected to a tongue 82 pivotallyconected to the pin 84 of a clevis block 86. The tongue 82 is providedwith a self-aligning bushing assembly 88 similar to the bushing assembly70. The clevis block 86 is rigidly affixed to a bracket 90 mounted onthe side of the tundish 10.

The hydraulic cylinder 74 is utilized for both initially leveling thetundish and for dumping same. The center of gravity 91 of the tundish isso disposed that, referring to FIG. 2, the tundish 10 has a clockwisemoment which is balanced by the cylinder 74.

Mounted on the beam 26 is a heat shield 92 adapted to protect theabove-described skewing and dumping mechanisms from the intense heat ofthe molten metal in the tundish 10.

The subject apparatus operates substantially as follows:

Assuming the nozzles of the tundish 10 are misaligned with respect tothe mold 12, the tundish is skewed by rotating one or both of the wheels42, depending upon the degree of misalignment. Rotation of the wheel 42results in either extending or retracting the shaft housing 48 andimparts a rotary motion to the trunnion seat 32.

By reason of the arrangement of the connecting rod 58 and the block 60,any change in the horizontal position of the trunnion as a result of theextension or retraction of the shaft 40 is transformed into asubstantially equal change in the horizontal position of the block 60.has much as the block 60 is also connected to the tundish 10 at bracket90, by means of hydraulic cylinder 74, bracket 90 will change itshorizontal position by an amount substantially equal to the change inhorizontal position of block 60. Thus, skewing of the tundish 10 resultsin substantially no rotation of the tundish about its trunnions, and thetundish remains level.

To dump the tundish 10, all that is required is to retract the shaft 80of the hydraulic cylinder 74, as is shown in FIG. 3. As can be seen, themotion of the dumping mechanism is substantially independent of themotion of the skewing mechanism.

While the subject invention has been described with reference to atundish having a plurality of nozzles, which generally requires askewing motion to center said nozzles with respect to the mold, theinvention may also be used for centering a tundish having but one nozzletherein. In this case, no skewing is necessary, and the tundish nozzlemay be centered by rotating both of the wheels 42 in the same direction.

I claim:

1. In a vertical continuous casting machine,

(a) a support frame including two horizontal members,

spaced apart, disposed above a vertical mold,

(b) a trunnion seat pivotally mounted on each of said horizontalmembers,

(c) a tundish, comprising a hollow vessel having a nozzle in the bottomthereof and provided with trunnions at the sides thereof, said trunnionsbeing rotatably mounted in said trunnion seats,

(d) means slidably mounted on each of said horizontal members,

(e) means for separately rotating each of said trunnion seats about itspivot,

(f) means linking each of said trunnion seats and means ((1) whereby anychange in the horizontal position of said trunnion as a result of therotation of its trunnion seat is transformed into a substantially equalchange in the horizontal position of means (d), and

(g) means, pivotally mounted on said tundish and means (d), having aretracted and an extended position for controlling the rotation of thetundish about said trunnions.

2. Apparatus as recited in claim 1, in which each of said trunnions isin substantial vertical alignment with its respective trunnion seatpivot.

3. Apparatus as recited in claim 2, in which:

(i) said trunnions are provided with a spherical bearing surface, and

(ii) the means pivotally mounting means (g) to said tundish and saidmeans (d) comprises self-aligning bearings.

4. Apparatus as recited in claim 1, in which said tundish has aplurality of nozzles in the bottom thereof.

References Cited UNITED STATES PATENTS 3,459,312 8/1969 Britcher et al.164335 X J. SPENCER OVERHOLSER, Primary Examiner I. E. ROETHEL,Assistant Examiner US Cl. X.R.

